Known for sliding in spurts, this slick speed demon has advanced some 1000 metres since June. The Medvezhiy glacier has covered more distance in the latest downslide than it has in any other in at least 22 years.

This satellite photo shows the glacier's progression as of 23 July. The glacier extended to just the "ankle" in the foot-like protrusion in early May.

Located in the Pamir Mountains of Tajikistan, the glacier is now blocking the Abdukagor River, prompting concerns over flooding. A glacial lake up to 200 metres deep and 350 metres wide has formed behind the wall of ice at its terminus. During its last major surges in 1962 and 1973, the glacier advanced as much 2 kilometres, later releasing 20 million cubic metres of water once the river breached the glacial ice dams.